3631243 - Unable to upload certain file types (e.g. PDF, JPG, JPEG, etc.) in application transactions due to message "Error occurred during import - SO424"

• User cannot upload certain file types (e.g. PDF, JPG, JPEG, etc.) in application transactions.
• The system shows error: Error occurred during import - Message No. SO424
• Long text of the message:

Diagnosis: An error occured during the import of a file.

System Response: The import was not carried out.

Procedure: If the document is still open in the application, you need to close it before you carry out a new import. This error message may indicate a SAP-GUI problem. The cause could be an error during data conversion, for example. Report the error to your system administrator.

Customer reports they do not face the same issue in production environment.

• Screen shot of the long text of the message:
  
  
  
   "Image/data in this KBA is from SAP internal systems, sample data, or demo systems. Any resemblance to real data is purely coincidental." 

• SAP Business Technology Platform
• SAP Basis release independent

Error occurred during import, SO424, MIME type of the uploaded file is blocked according to your repository configuration,  , KBA , BC-SRV-COM , Communication Services: Mail, Fax, SMS, Telephony , Problem